NOTE: as a good coding practice, there should be only one portidentifier per line, as shown below.
注意：作为一个编码的好习惯，最好一行声明一个标识符，如下所示。
2
The addresses specify the two machines at each end while the port Numbers ensure that the connection between the two computers has a unique identifier.
地址用来标识一个连接两端的两台计算机，而端口号则确保两台计算机之间的连接都有一个唯一的标识符。
3
A server mode connection is created by passing a string that identifies an end point (protocol dependent identifier, for example, a port number) on the local host to the Connector.open method.